• 미생물학회지
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• 제13권4호
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• pp.165-172
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• 1975

A strain of Azotobacter species was isolated from the surface sea water of Kwang-yang Bay in Korea and was identified as Azotobacter insignis. In order to reveal the natural habitat of this microorganism, growth at various salt concentrations was tested with the result of 3% NaCl beins optimum. Only slight growth was detected in the absence of NaCl. This result was thought to prove (in part) that the natural habitat of the strain dealt with is sea water. Fairly good growth was obtained at 6% NaCl concentration. The study of effects of salt on the growth og this strain to various temperatures and pHs has shown that temperature $30{\circ}C and pH 7.0 are Optimum.

• 설비공학논문집
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• 제2권1호
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• pp.49-62
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• 1990

The forced cooling system has been widely applied to passing more electric current in the underground power transmission cable technology. In this paper, the optimum cooling span of the in-trough-indirect water cooling method within an electric tunnel was investigated. A parametric study was performed for the cable currents, the coolant flow rates, and the coolant inlet temperatures. As a result, the temperature of the inlet air has been found as the most important parameter in determination of the optimum cooling span.

• 한국태양에너지학회 논문집
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• 제28권5호
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• pp.1-7
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• 2008

Flashed steam system is one of the important geothermal power production methods. In this paper, optimum operations and performances of single and double flash systems are presented. It is shown that double flash system can produce about 26.5% more power than single flash system. Temperature of geothermal water($T_R$) is the most important parameter in the geothermal system. Optimum single and double flash temperatures and net power produced with these optimum conditions are expressed as a function of $T_R$ in this study. Thus net power output from geothermal resources can be estimated with the results of this work. Condenser Temperature($T_{con}$) is also important and the net power production can be shown as a function of ($T_R-T_{con}$. Volume flow rate per unit power is also to be considered as the condenser temperature decreases.

• 한국식품과학회지
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• 제34권1호
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• pp.65-72
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• 2002

식혜 제조시 당화에 영향을 미치는 인자인 엿기름 추출온도와 시간, 엿기름과 물의 비율, 밥의 양을 반응표면분석법의 중심합성계획에 따라 설계하여 각각 조건들의 영향을 dual cathod system으로 구성된 바이오센서로 행하였을 때 포도당과 맥아당의 측정은 엿기름 추출온도 및 각각의 조건들은 포도당과 맥아당의 최적조건이 약간은 다른 결과를 보였는데 포도당에서는 $60^{\circ}C$, 맥아당은 $55^{\circ}C$에서 최적의 온도를 나타내었고 엿기름 추출시간은 포도당이 6시간 30분, 맥아당은 5시간 45분이었으며 물과 엿기름의 비율은 포도당과 맥아당 각각 1:6.3, 1:8.8이었고 엿기름 추출액과 고두밥의 양에서는 0.48%는 포도당, 0.6%는 맥아당이 최적조건이었다. 반응표면분석법에 의하여 유의차를 검증한 결과 그 상관관계를 비교했을 때 유의성이 높게 나타났다.

• 한국수산과학회지
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• 제21권3호
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• pp.145-149
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• 1988

Macrohrachium koreana의 유생에 대한 수온, 염분 농도 및 먹이의 영향을 조사한 결과는 다음과 같다. 염분농도가 증가 할수록 생존율이 감소했고, 제2기 유생은 $40\%$ 해수농도$(13.7\%_{\circ})$이상 일때는 48시간내에 대부분 죽었다. 수온이 상승할 수록 각 stage별 소요기간이 짧아졌으며, 이들 유생의 성장에 알맞는 수온은 $22^{\circ}C\~26^{\circ}C$로 나타났고, 수온 $30^{\circ}C$에서는 생존율이 떨어졌다. 먹이효과는 바지락 급식구에서 가장 생존율이 높았고 무급식구와 분말급식구에서는 제4기 유생이 될때까지 대부분 죽었다.

• KSBB Journal
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• 제18권5호
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• pp.418-423
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• 2003

발효조의 냉각수 공급 제어 신호와 냉각수의 유출입 지점의 온도를 온라인으로 측정하여 이 값들로부터 냉각량을 추정할 수 있는 실험식을 얻었다. 회분식 배양을 통하여 냉각량이 온라인으로 측정될 수 있음을 확인하였고 기질의 재투입시 냉각량의 변화를 통하여 유가배양의 제어변수로 활용할 수 있음을 점검하였다. 미리 프로그램된 목표 냉각량의 증가곡선에 따라 냉각량이 증가되면서 세포가 자라도록 유가배양을 실시하였다. 본 연구를 통하여 냉각량의 온라인 측정방법을 제시하였고 이를 유가배양 제어변수로 활용하여 세포의 성장속도를 조절할 수 있음을 보였다.

• 한국수산과학회지
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• 제48권3호
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• pp.322-328
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• 2015

Three feeding trials were conducted to investigate the optimal feeding rates of subadult Korean rockfish Sebastes schlegeli at low, optimal and high water temperatures. In Exp-I, triplicate groups of fish (248 g) were fed a commercial diet (CD) with five different feeding rates of 0.1%, 0.2%, 0.4%, 0.6% and 0.8% body weight per day for 10 weeks at the low temperature ($11.6-15.2^{\circ}C$). In Exp-II, fish (129 g) were fed the same CD with five different feeding rates of 0.4%, 0.8%, 1.2%, 1.6% and 2.0% body weight per day for 10 weeks at the optimal temperature ($16.0-18.8^{\circ}C$). In Exp-III, fish (85.7 g) were fed the same CD with five different feeding rates of 0.4%, 0.8%, 1.2%, 1.6% and 2.0% body weight per day for 12 weeks at the high temperature ($21.0-28.5^{\circ}C$). The optimal feeding rates in the low, optimal, and high water temperatures were estimated to be 0.56%, 0.93% and 1.17% body weight per day, respectively, for subadult Korean rockfish.

• 한국식품저장유통학회지
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• 제8권2호
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• pp.140-145
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• 2001

Although the drying times of paddies were significantly shortened by the application of higher drying temperatures, the 12, 10 and 8 hours were needed for the reduction of moisture contents from 23.55 to 15% at the temperatures of 45, 50 and 55$\^{C}$, respectively. Milling yields(MY) and rice rates(HRR) were decreased by increasing of the drying temperature. The MY ratios were 75.50, 75.42 and 75.31% and HRR were 93.28, 92.14 and 91.12% in drying temperature of 40, 50 and 55$\^{C}$, respectively. In the milling processes of tough rice with the used of a milling machine equipped with both of abrasive and friction types in a body, the reduction rates of bran and the occurrence of broken rice increased with the pressures at outlet or the recycled passing tines. In the process for humidified friction whitening of rice, it was found that the optimum addition rate of water for the best quality was the 11.2 liters per tone of white rice.

• 해양환경안전학회지
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• 제27권1호
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• pp.119-126
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• 2021

본 연구에서는 실내에서 다양한 수온과 염분 조건에서 유독와편모조류 Alexandrium catenella(Group I)의 생장과 함께 마비성패독의 함량을 조사하였다. A. catenella의 수온과 염분 최적생장은 각각 20~30℃과 20~30 psu였으며, 광온성과 광염성종으로 나타났다. A. catenella는 낮은 수온 구간(10℃와 15℃)에서 독함량과 독성이 높게 나타났으며, 염분에 따라서는 차이가 크지 않았다. 따라서 15℃이하의 수온에서 본 종주와 같은 생리적인 특성을 가진 유독와편모조류가 우점한다면, 이매패류는 빠르게 독화될 가능성이 있다. 향후 A. catenella의 출현에 따른 마비성패독 예찰·예보를 위해 다양한 환경변화에 따른 A. catenella의 다른 종주와 상업적인 이매패류 독화에 대한 연구가 더 필요한 것으로 판단된다.

• ETRI Journal
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• 제19권2호
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• pp.59-70
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• 1997

A study on the operation of a heat pipe with two heat sources has been performed to optimize the heat distribution of satellite equipment. A numerical modeling is used to predict the temperature profile for the heat pipe assuming cylindrical two-dimensional laminar flow for the vapor, and the conduction heat transfer for the wall and wick. An experimental study using the copper-water heat pipe with the length of 0.45 m has been performed to evaluate the numerical model and to compare the temperature distribution at the outer wall for the non-uniform heat distribution. The results on temperature profiles for the heat input range from 29 W to 47 W on each heater are presented. Also the correlation between the heat input and the temperature increase is presented for the optimum distribution on two heaters. The result shows that the outer wall temperature can be controlled by redistribution of heat sources. It is also concluded that the heat source closer to the condenser can carry more heat while maintaining lower temperatures at the outer wall.